Solder & Low-Melting Alloy Sn5Pb95
ASTM Sn5 · JIS H5A · GB HLSnPb5-95
Sn5Pb95 is a very high-lead tin–lead solder (5% Sn, 95% Pb; H5A, HLSnPb5-95) melting above roughly 300 °C, used as a high-temperature die attach and step-solder in power modules.
Reference datasheet — Sn5Pb95 is not in the instant-quote catalog. Upload your part and an engineer will quote it in this grade or suggest the closest stocked equivalent.
What is Sn5Pb95?
Sn5Pb95 is a very high-lead tin–lead solder (5% Sn, 95% Pb; H5A, HLSnPb5-95) melting above roughly 300 °C, used as a high-temperature die attach and step-solder in power modules. It holds a RoHS exemption because no viable lead-free substitute exists at this melting point, and is supplied as bar, solid and flux-cored wire, ribbon, preform and paste. The alloy is very soft: 12 MPa yield, 24 MPa tensile, 45% elongation, 8 HB, with service to 175 °C. Handling generates lead swarf and dust, and joints need thorough flux cleaning; Sn10Pb90 is the nearest lower-melting option. Sn5Pb95 has a density of 11 g/cm³ (0.397 lb/in³), heavier than 89% of solder & low-melting alloy grades. It melts at 308°C (586 °F). Sn5Pb95 has a yield strength of 12 MPa (1.74 ksi) and a tensile strength of 24 MPa (3.48 ksi) — weaker than 88% of solder & low-melting alloy grades. Elongation at break is 45% and the elastic modulus is 16 GPa (2.32 Msi).
What is Sn5Pb95 used for?
- power module die-attach
- high-reliability step soldering
- high-temperature RoHS-exempt joints
Advantages
- High service temperature — 175°C (347 °F), better than 97% of solder & low-melting alloy grades
- Ductile — tolerates forming and impact — 45%, better than 84% of solder & low-melting alloy grades
- Low embodied carbon — 2.6 kg CO₂/kg, better than 84% of solder & low-melting alloy grades
Limitations
- Heavy — 11 g/cm³ (0.397 lb/in³), worse than 89% of solder & low-melting alloy grades
- Low strength — 12 MPa (1.74 ksi), worse than 88% of solder & low-melting alloy grades
- Low stiffness — 16 GPa (2.32 Msi), worse than 88% of solder & low-melting alloy grades
- Hard to polish — 20/100, worse than 88% of solder & low-melting alloy grades
- Poor heat conductor — 30 W/m·K (17.3 BTU/hr·ft·°F), worse than 79% of solder & low-melting alloy grades
Sn5Pb95 properties
Typical room-temperature values; bars are the position among solder & low-melting alloy grades.
Physical3
Sn5Pb95 has a density of 11 g/cm³ (0.397 lb/in³), heavier than 89% of solder & low-melting alloy grades. It melts at 308°C (586 °F).
Mechanical10
Sn5Pb95 has a yield strength of 12 MPa (1.74 ksi) and a tensile strength of 24 MPa (3.48 ksi) — weaker than 88% of solder & low-melting alloy grades. Elongation at break is 45% and the elastic modulus is 16 GPa (2.32 Msi).
Thermal6
Sn5Pb95 is rated for continuous service to 175°C (347 °F). It conducts heat at 30 W/m·K (17.3 BTU/hr·ft·°F), worse than 79% of solder & low-melting alloy grades. Thermal expansion is 29 µm/m·K (16.1 µin/in·°F).
Electrical3
Sn5Pb95 conducts electricity at 8.2 % IACS, worse than 71% of solder & low-melting alloy grades.
Chemical & Environmental3
Corrosion resistance is fair (45/100), worse than 52% of solder & low-melting alloy grades.
Sustainability4
Producing a kilogram of Sn5Pb95 takes about 42 MJ of energy and emits 2.6 kg of CO₂ — less than 84% of solder & low-melting alloy grades. Typical recycled content is 55%.
Manufacturability6
Sn5Pb95's machinability is poor (25/100, worse than 82% of solder & low-melting alloy grades); formability excellent (95/100).
Common Calculations5
Values are nominal handbook figures for design screening. Certified mill or lot data ships with every FabDigit order on request.
Strength versus weight in the solder & low-melting alloy family
Yield strength against density for every solder & low-melting alloy grade FabDigit runs. Sn5Pb95 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with Sn5Pb95
Is Sn5Pb95 easy to machine?
Essentially never machined — too soft and gummy; shear, stamp or coin it instead, and control lead dust/swarf as hazardous waste.
Can Sn5Pb95 be welded?
Not weldable as a structural alloy; it is itself a filler — joints are made by soldering at 340–380 °C with RMA/RA flux or in forming-gas/formic-acid reflow.
Can Sn5Pb95 be formed, bent or molded?
Extrudes, rolls and stamps easily at room temperature (recrystallizes at RT), so preforms, ribbon and wire are made without annealing steps.
Sn5Pb95 chemical composition (wt %)
Limits by weight percent from the governing specification, written the way the spec states them — a single maximum for impurities, a range for alloying elements, and the base element as balance. Nominal is the typical mid-range value.
| Element | Spec limit (wt %) | Nominal |
|---|---|---|
| SnASTM B32 alloy grade Sn5 | 4.5 – 5.5 | 5 |
| Sbimpurity limit | ≤ 0.5 | |
| Bi | ≤ 0.25 | |
| Cu | ≤ 0.08 | |
| Ag | ≤ 0.02 | |
| Fe | ≤ 0.02 | |
| Zn | ≤ 0.01 | |
| Al | ≤ 0.01 | |
| As | ≤ 0.03 | |
| Pbbalance, ~95 % | balance |
What surface finishes work on Sn5Pb95?
No plating or anodizing; surfaces dull to grey PbO quickly — clean flux residues thoroughly and handle with gloves due to lead toxicity.
Equivalent designations
Standards and trade names that resolve to Solder & Low-Melting Alloy Sn5Pb95 in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- ASTM
- Sn5
- GB (China)
- HLSnPb5-95
- JIS
- H5A
How much does Sn5Pb95 cost?
Sn5Pb95 is a high-cost solder & low-melting alloy ($$$$), pricier than about 78% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
Sn5Pb95 — frequently asked
What is Sn5Pb95 used for?
Sn5Pb95 is typically used for power module die-attach, high-reliability step soldering and high-temperature RoHS-exempt joints. In short: highest-melting Sn-Pb solder; roHS-exempt die attach; very soft, 8 HB.
What is the yield strength of Sn5Pb95?
Sn5Pb95 has a typical yield strength of 12 MPa (1.74 ksi) and a tensile strength of 24 MPa (3.48 ksi) — weaker than 88% of solder & low-melting alloy grades.
Is Sn5Pb95 easy to machine?
Not especially — machinability is rated poor (25/100, worse than 82% of solder & low-melting alloy grades). Essentially never machined — too soft and gummy; shear, stamp or coin it instead, and control lead dust/swarf as hazardous waste.
Can Sn5Pb95 be welded?
Not weldable as a structural alloy; it is itself a filler — joints are made by soldering at 340–380 °C with RMA/RA flux or in forming-gas/formic-acid reflow.
What surface finishes work on Sn5Pb95?
No plating or anodizing; surfaces dull to grey PbO quickly — clean flux residues thoroughly and handle with gloves due to lead toxicity.
Can Sn5Pb95 be formed, bent or molded?
Extrudes, rolls and stamps easily at room temperature (recrystallizes at RT), so preforms, ribbon and wire are made without annealing steps.
What is the maximum service temperature of Sn5Pb95?
Sn5Pb95 is rated for continuous use to about 175°C (347 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
How much does Sn5Pb95 cost?
Sn5Pb95 is a high-cost solder & low-melting alloy ($$$$), pricier than about 78% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
Sources
- ASTM B32 — Standard Specification for Solder Metal — ASTM International (2020)
- J-STD-006 — Requirements for Electronic Grade Solder Alloys — IPC/JEDEC (2017)
- ASM Handbook Vol.2 — Properties and Selection: Nonferrous Alloys (Lead and Tin Solders) — ASM International (1990)
- ASM Handbook Vol.6 — Welding, Brazing and Soldering (Solder Alloy Data) — ASM International (1993)
- High-lead solder alloy property sheets (Pb95Sn5 / Pb93.5Sn5Ag1.5) — Indium Corporation / Alpha Assembly (2022)
- GB/T 3131 (2020)
Property data is compiled from published supplier and standards handbooks and normalised for comparison; hardness values on non-Brinell scales are converted approximately for charting only. Manufacturability limits are FabDigit quote-engine defaults and may be relaxed by engineering review. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.